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Hiroyuki Kawamoto and Masaki UchiyamaWaseda University, Tokyo
LEAG-ICEUM-SRR: October 31, 2008 @Cape Canaveral
Electrostatic Cleaner of Lunar Dust on Solar Panel and
Optical Lens
NASA
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OutlineWe are developing a self-cleaning device of lunar dust on a solar panel and optical lens utilizing electrostatic force.
originally developed for toner transport in laser printer
applied for lunar exploration□ low power consumption with
compact power supply□ high cleaning performance with
transparent ITO electrodes□ effect of initial charge□ demonstration in lunar
environment (vacuum and low gravity)
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Switching of ±DC power supplies are
controlled by a μ-comp.
+HV
-HV
CH1
CH2
CH3
CH4
CH1
CH2
CH3
CH4
traveling wave
190 mm
Electrostatic Dust Cleaner Systemtraveling wave transport of particles
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Photograph of Lunar Dust Simulant
200X
Provided by Shimiz Corp.
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Experiment in Vacuum Chamber
vacuum chamber
vacuum pump
Pirani vacuum meter5 Pa (0.04 Torr)
cleaner
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Cleaning Rate
in air (100 Hz) in vacuum (100 Hz)
0
20
40
60
80
100
0 50 100 150 200frequency Hz
clea
ning
rate
%in vacuum, 1,000 Vin vacuum, 900 Vin vacuum, 800 Vin air, 1,000 Vin air, 900 Vin air, 800 V
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6i ii i i coulomb dipole mechanical adhesion im R mπη+ = + + + +
ix x F F F F g&& &
i ii i mechanical frictionI M= +θ M&&
(Air Drag) (Coulomb) (polarization) (collision) (adhesion) (gravity)
Numerical Simulation-calculated by Discrete Element Method-
↓0, in vacuum
( 1 : number of particles)i , ,N N= Lmi
FiMi
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Transport of Particles in Air and Vacuum
air
10 Pa
vacuum
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Cleaning Assisted by Ultrasonic Vibrator
cleaner with ITO electrodes
ultrasonic vibrator (28 kHz)
10
80
85
90
95
100
in air in vacuum
clea
ning
rate
w
t%
without vibrator
Improved Cleaning Performance with Ultrasonic Vibrator
80
85
90
95
100
in air in vacuum
clea
ning
rate
w
t%
without vibratorwith vibrator
98 %
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Transmission Rate of Light before/after Operation
0
20
40
60
80
100
300 400 500 600 700 800wave length nm
trans
mis
sion
rate
of
%
virginin vacuumin air
only 4 % reduction
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＋ ＋＋
corona discharge
＋
±5 kV
pin electrode
Cleaning Performance of Initially Charged Dust
Initially charged dust can be cleaned successfully.
0
20
40
60
80
100
no charge positivelycharged
negativelycharged
clea
ning
rate
%
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on the earth700 V 10 Hz
• 1 G• in air
on the moon700 V 10 Hz
• 1/6 G• in vacuum
Cleaning Performance on the Moon
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Power Consumption@ 1 m2 cleaner
0
5
10
15
0 200 400 600 800 1000appled voltage V (@ 10 Hz)
pow
er lo
ss
W/m
2
0
20
40
60
80
0 20 40 60 80 100frequency Hz (@ 800 V)
pow
er lo
ss W
/m2
estimated power consumption: 7 W ×30 sec. = 0.06 Wh for 1 m2 cleaner
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Concluding Remarks
Numerical and experimental investigations were carried out on the electrostatic transport of particles to apply for the cleaning of lunar soil and dust.
□ compact & light power supply□ transparent IOT conveyer□ demonstration in vacuum□ high cleaning performance□ effect of initial charge
□ low power consumption□ performance prediction on the moon□ high transparency
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Application of Electrostatic Particle Transport for Lunar Resource Utilization
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Thank you for your attention.
For more informationHiroyuki Kawamoto, Prof.Waseda UniversityShinjuku, TokyoPhone/FAX: +81-3-5286-3914E-mail: [email protected]://www.kawamoto.mech.waseda.ac.jp/kawa/
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Electrostatic Cleaner of Lunar Dust Adhered to Spacesuits
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We need textile of spacesuits for the demonstration of our cleaner.
Please provide for us.
We will report the results of our investigation.
We need your support !!
